RESUMO
Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an epigenetic regulator that plays critical roles in tumours. However, the DNA methylation alteration patterns driven by UHRF1 and the related differentially expressed tumour-related genes remain unclear. In this study, a UHRF1-shRNA MCF-7 cell line was constructed, and whole-genome bisulfite sequencing and RNA sequencing were performed. The DNA methylation alteration landscape was elucidated, and DNA methylation-altered regions (DMRs) were found to be distributed in both gene bodies and adjacent regions. The DMRs were annotated and categorized into 488 hypermethylated/1696 hypomethylated promoters and 1149 hypermethylated/5501 hypomethylated gene bodies. Through an integrated analysis with the RNA sequencing data, 217 methylation-regulated upregulated genes and 288 downregulated genes were identified, and these genes were primarily enriched in nervous system development and cancer signalling pathways. Further analysis revealed 21 downregulated oncogenes and 15 upregulated TSGs. We also showed that UHRF1 silencing inhibited cell proliferation and migration and suppressed tumour growth in vivo. Our study suggested that UHRF1 and the oncogenes or TSGs it regulates might serve as biomarkers and targets for breast cancer treatment.
Assuntos
Proteínas Estimuladoras de Ligação a CCAAT , Metilação de DNA , Regulação Neoplásica da Expressão Gênica , Ubiquitina-Proteína Ligases , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Humanos , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Células MCF-7 , Feminino , Proliferação de Células/genética , Animais , Regiões Promotoras Genéticas , Camundongos , Epigênese Genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Movimento Celular/genéticaRESUMO
The transcription factor FOXM1, which plays critical roles in cell cycle progression and tumorigenesis, is highly expressed in rapidly proliferating cells and various tumor tissues, and high FOXM1 expression is related to a poor prognosis. However, the mechanism responsible for FOXM1 dysregulation is not fully understood. Here, we show that ABL1, a nonreceptor tyrosine kinase, contributes to the high expression of FOXM1 and FOXM1-dependent tumor development. Mechanistically, ABL1 directly binds FOXM1 and mediates FOXM1 phosphorylation at multiple tyrosine (Y) residues. Among these phospho-Y sites, pY575 is indispensable for FOXM1 stability as phosphorylation at this site protects FOXM1 from ubiquitin-proteasomal degradation. The interaction of FOXM1 with CDH1, a coactivator of the E3 ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C), which is responsible for FOXM1 degradation, is significantly inhibited by Y575 phosphorylation. The phospho-deficient FOXM1(Y575F) mutant exhibited increased ubiquitination, a shortened half-life, and consequently a substantially decreased abundance. Compared to wild-type cells, a homozygous Cr-Y575F cell line expressing endogenous FOXM1(Y575F) that was generated by CRISPR/Cas9 showed obviously delayed mitosis progression, impeded colony formation and inhibited xenotransplanted tumor growth. Overall, our study demonstrates that ABL1 kinase is involved in high FOXM1 expression, providing clear evidence that ABL1 may act as a therapeutic target for the treatment of tumors with high FOXM1 expression.
RESUMO
The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a worldwide threat in the past 3 years. Although it has been widely and intensively investigated, the mechanism underlying the coronavirus-host interaction requires further elucidation, which may contribute to the development of new antiviral strategies. Here, we demonstrated that the host cAMP-responsive element-binding protein (CREB1) interacts with the non-structural protein 13 (nsp13) of SARS-CoV-2, a conserved helicase for coronavirus replication, both in cells and in lung tissues subjected to SARS-CoV-2 infection. The ATPase and helicase activity of viral nsp13 were shown to be potentiated by CREB1 association, as well as by Protein kinase A (PKA)-mediated CREB1 activation. SARS-CoV-2 replication is significantly suppressed by PKA Cα, cAMP-activated protein kinase catalytic subunit alpha (PRKACA), and CREB1 knockdown or inhibition. Consistently, the CREB1 inhibitor 666-15 has shown significant antiviral effects against both the WIV04 strain and the Omicron strain of the SARS-CoV-2. Our findings indicate that the PKA-CREB1 signaling axis may serve as a novel therapeutic target against coronavirus infection. IMPORTANCE: In this study, we provide solid evidence that host transcription factor cAMP-responsive element-binding protein (CREB1) interacts directly with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) helicase non-structural protein 13 (nsp13) and potentiate its ATPase and helicase activity. And by live SARS-CoV-2 virus infection, the inhibition of CREB1 dramatically impairs SARS-CoV-2 replication in vivo. Notably, the IC50 of CREB1 inhibitor 666-15 is comparable to that of remdesivir. These results may extend to all highly pathogenic coronaviruses due to the conserved nsp13 sequences in the virus.
Assuntos
RNA-Polimerase RNA-Dependente de Coronavírus , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Proteínas Quinases Dependentes de AMP Cíclico , Interações entre Hospedeiro e Microrganismos , SARS-CoV-2 , Proteínas não Estruturais Virais , Replicação Viral , Humanos , Adenosina Trifosfatases/metabolismo , Antivirais/farmacologia , RNA-Polimerase RNA-Dependente de Coronavírus/metabolismo , COVID-19/virologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/antagonistas & inibidores , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/deficiência , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Subunidades Catalíticas da Proteína Quinase Dependente de AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , DNA Helicases/metabolismo , Concentração Inibidora 50 , RNA Helicases/metabolismo , SARS-CoV-2/classificação , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/enzimologia , SARS-CoV-2/crescimento & desenvolvimento , Transdução de Sinais/efeitos dos fármacos , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos , Feminino , Animais , CamundongosRESUMO
Excessive inflammatory responses contribute to the pathogenesis and lethality of highly pathogenic human coronaviruses, but the underlying mechanism remains unclear. In this study, the N proteins of highly pathogenic human coronaviruses, including severe acute respiratory syndrome coronavirus (SARS-CoV), middle east respiratory syndrome coronavirus (MERS-CoV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), were found to bind MASP-2, a key serine protease in the lectin pathway of complement activation, resulting in excessive complement activation by potentiating MBL-dependent MASP-2 activation, and the deposition of MASP-2, C4b, activated C3 and C5b-9. Aggravated inflammatory lung injury was observed in mice infected with adenovirus expressing the N protein. Complement hyperactivation was also observed in SARS-CoV-2-infected patients. Either blocking the N protein:MASP-2 interaction, MASP-2 depletion or suppressing complement activation can significantly alleviate N protein-induced complement hyperactivation and lung injury in vitro and in vivo. Altogether, these data suggested that complement suppression may represent a novel therapeutic approach for pneumonia induced by these highly pathogenic coronaviruses.
Assuntos
COVID-19 , Lesão Pulmonar , Animais , COVID-19/genética , Lectina de Ligação a Manose da Via do Complemento/genética , Proteínas do Nucleocapsídeo de Coronavírus , Humanos , Inflamação/genética , Serina Proteases Associadas a Proteína de Ligação a Manose/genética , Serina Proteases Associadas a Proteína de Ligação a Manose/metabolismo , Camundongos , SARS-CoV-2RESUMO
The anti-apoptotic protein HAX-1 has been proposed to modulate mitochondrial membrane potential, calcium signaling and actin remodeling. HAX-1 mutation or deficiency results in severe congenital neutropenia (SCN), loss of lymphocytes and neurological impairments by largely unknown mechanisms. Here, we demonstrate that the activation of c-Abl kinase in response to oxidative or genotoxic stress is dependent on HAX-1 association. Cellular reactive oxygen species (ROS) accumulation is inhibited by HAX-1-dependent c-Abl activation, which greatly contributes to the antiapoptotic role of HAX-1 in stress. HAX-1 (Q190X), a loss-of-function mutant responsible for SCN, fails to bind with and activate c-Abl, leading to dysregulated cellular ROS levels, damaged mitochondrial membrane potential and eventually apoptosis. The extensive apoptosis of lymphocytes and neurons in Hax-1-deficient mice could also be remarkably suppressed by c-Abl activation. These findings underline the important roles of ROS clearance in HAX-1-mediated anti-apoptosis by c-Abl kinase activation, providing new insight into the pathology and treatment of HAX-1-related hereditary disease or tumorigenesis.
Assuntos
Proteínas Reguladoras de Apoptose , Apoptose , Animais , Apoptose/fisiologia , Síndrome Congênita de Insuficiência da Medula Óssea , Camundongos , Neutropenia/congênito , Espécies Reativas de OxigênioRESUMO
Ebola virus (EBOV), one of the deadliest viruses, is the cause of fatal Ebola virus disease (EVD). The underlying mechanism of viral replication and EBOV-related hemorrhage is not fully understood. Here, we show that EBOV VP35, a cofactor of viral RNA-dependent RNA polymerase, binds human A kinase interacting protein (AKIP1), which consequently activates protein kinase A (PKA) and the PKA-downstream transcription factor CREB1. During EBOV infection, CREB1 is recruited into EBOV ribonucleoprotein complexes in viral inclusion bodies (VIBs) and employed for viral replication. AKIP1 depletion or PKA-CREB1 inhibition dramatically impairs EBOV replication. Meanwhile, the transcription of several coagulation-related genes, including THBD and SERPINB2, is substantially upregulated by VP35-dependent CREB1 activation, which may contribute to EBOV-related hemorrhage. The finding that EBOV VP35 hijacks the host PKA-CREB1 signal axis for viral replication and pathogenesis provides novel potential therapeutic approaches against EVD.
Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ebolavirus/fisiologia , Doença pelo Vírus Ebola/metabolismo , Doença pelo Vírus Ebola/virologia , Humanos , Proteínas Nucleares/metabolismo , Proteínas do Nucleocapsídeo , Proteínas Virais Reguladoras e Acessórias/metabolismoRESUMO
Cytoskeletal microtubules (MTs) are nucleated from γ-tubulin ring complexes (γTuRCs) located at MT organizing centers (MTOCs), such as the centrosome. However, the exact regulatory mechanism of γTuRC assembly is not fully understood. Here, we showed that the nonreceptor tyrosine kinase c-Abl was associated with and phosphorylated γ-tubulin, the essential component of the γTuRC, mainly on the Y443 residue by in vivo (immunofluorescence and immunoprecipitation) or in vitro (surface plasmon resonance) detection. We further demonstrated that phosphorylation deficiency significantly impaired γTuRC assembly, centrosome construction, and MT nucleation. c-Abl/Arg deletion and γ-tubulin Y443F mutation resulted in an abnormal morphology and compromised spindle function during mitosis, eventually causing uneven chromosome segregation. Our findings reveal that γTuRC assembly and nucleation function are regulated by Abl kinase-mediated γ-tubulin phosphorylation, revealing a fundamental mechanism that contributes to the maintenance of MT function.
Assuntos
Centro Organizador dos Microtúbulos , Microtúbulos , Proteínas Proto-Oncogênicas c-abl , Tubulina (Proteína) , Centrossomo/metabolismo , Centro Organizador dos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-abl/genética , Proteínas Proto-Oncogênicas c-abl/metabolismo , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismoRESUMO
Nonreceptor tyrosine kinase c-Abl participates in several cellular processes by phosphorylating transcription factors or cofactors. c-Abl binds and phosphorylates four-and-a-half-LIM-only protein 2 (FHL2), but the identity of the phosphorylation sites and their contribution to cell cycle regulation is unclear. In this study, we demonstrate that c-Abl highly phosphorylates FHL2 at Y97, Y176, Y217, and Y236 through mass spectrometry and tyrosine-to-phenylalanine (Y â F) mutant analysis. Proliferation was inhibited in cells expressing wild-type (WT) FHL2 but not cells expressing the phosphorylation-defective mutant FHL2(4YF). Moreover, FHL2 contributed to cell cycle arrest at G2/M induced by ionizing radiation (IR). FHL2 WT but not FHL2(4YF) rescued FHL2 function in FHL2-depleted cells by causing IR-induced G2/M arrest. These results demonstrate that c-Abl regulates cell cycle progression by phosphorylating FHL2.
Assuntos
Proteínas com Homeodomínio LIM/metabolismo , Proteínas Musculares/metabolismo , Proteínas Proto-Oncogênicas c-abl/metabolismo , Fatores de Transcrição/metabolismo , Proliferação de Células , Células Cultivadas , Pontos de Checagem da Fase G2 do Ciclo Celular , Humanos , Proteínas com Homeodomínio LIM/deficiência , Proteínas Musculares/deficiência , Fosforilação , Radiação Ionizante , Fatores de Transcrição/deficiênciaRESUMO
The transcription factor Runx1 is an essential regulator of definitive hematopoiesis, megakaryocyte (MK) maturation, and lymphocyte differentiation. Runx1 mutations that interfere with its transcriptional activity are often present in leukemia patients. Recent work demonstrated that the transcriptional activity of Runx1 is regulated by kinase-mediated phosphorylation. In this study, we showed that c-Abl, but not Arg tyrosine kinase, associated with Runx1 both in cultured cells and in vitro. c-Abl-mediated tyrosine phosphorylation in the Runx1 transcription inhibition domain negatively regulated the transcriptional activity of Runx1 and inhibited Runx1-mediated MK maturation. Consistent with these findings, increased numbers of MKs were detected in the spleens and bone marrow of abl gene conditional knockout mice. Our findings demonstrate an important role of c-Abl kinase in Runx1-mediated MK maturation and platelet formation and provide a potential mechanism of Abl kinase-regulated hematopoiesis.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Megacariócitos/metabolismo , Proteínas Proto-Oncogênicas c-abl/metabolismo , Animais , Sítios de Ligação , Plaquetas/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/química , Regulação da Expressão Gênica , Células HEK293 , Humanos , Células K562 , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-abl/genética , Transcrição GênicaRESUMO
BACKGROUND Studies have found that c-Abl oncogenic kinases may regulate gene transcription by RNA polymerase II phosphorylation or by direct regulation of specific transcription factors or coactivators. However, the global regulation of differential gene expression by c-Abl/Arg is largely unknown. In this study, differentially expressed genes (DEGs) regulated by c-Abl/Arg were identified, and related cellular functions and associated pathways were investigated. MATERIAL AND METHODS RNA obtained from wild-type and c-Abl/Arg gene-silenced MCF-7 cells was analyzed by RNA-Seq. DEGs were identified using edgeR software and partially validated by qRT-PCR. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to explore the potential functions of these DEGs. RESULTS A total of 1,034 DEGs were significantly regulated by c-Abl/Arg (399 were up-regulated and 635 were down-regulated after c-Abl/Arg double knockdown). GO and KEGG analyses showed that the DEGs were primarily involved in cellular metabolic processes, neurodegenerative disease, the metabolic process and signaling pathway of cAMP, angiogenesis, and cell proliferation. CONCLUSIONS Our data collectively support the hypothesis that c-Abl/Arg regulate differential gene expression, providing new insights into the biological functions of c-Abl and Arg.
Assuntos
Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Proteínas Tirosina Quinases/genética , Proteínas Proto-Oncogênicas c-abl/genética , Linhagem Celular Tumoral , Proliferação de Células , AMP Cíclico/metabolismo , Regulação para Baixo , Inativação Gênica , Humanos , Células MCF-7 , Neovascularização Patológica , Fosforilação , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-abl/metabolismo , Análise de Sequência de RNA , Transdução de Sinais , Software , Fatores de Transcrição/metabolismo , Transcrição GênicaRESUMO
Oxidative stress contributes to the oxidative modification of cellular components, including lipids, proteins and DNA, and results in DNA damage, cell cycle arrest, cellular dysfunction and apoptosis. However, the mechanism underlying oxidative stress-induced mitotic abnormalities is not fully understood. In this study, we demonstrated that exogenous and endogenous reactive oxygen species (ROS) promoted mitotic arrest. Delayed formation and abnormal function of the mitotic spindle, which directly impeded mitosis and promoted abnormal chromosome separation, was responsible for ROS-induced mitotic arrest. As a key regulator of mitotic spindle assembly, Aurora A kinase was hyperphosphorylated in early mitosis under oxidative stress, which may disturb the function of Aurora A in mitotic spindle formation. Our findings identified a mechanism by which ROS regulate mitotic progression and indicated a potential molecular target for the treatment of oxidative stress-related diseases.
Assuntos
Aurora Quinase A/metabolismo , Pontos de Checagem do Ciclo Celular , Estresse Oxidativo , Fuso Acromático/metabolismo , Apoptose , Células HEK293 , Células HeLa , Humanos , Peróxido de Hidrogênio/farmacologia , Células MCF-7 , Mitose , Fosforilação , Processamento de Proteína Pós-Traducional , Transporte Proteico , Vitamina K 3/farmacologiaRESUMO
The ubiquitin-proteasome system is a vital proteolytic pathway required for cell homeostasis. However, the turnover mechanism of the proteasome subunit itself is still not understood. Here, we show that the 20S proteasome subunit PSMA7 is subjected to ubiquitination and proteasomal degradation, which was suppressed by PSMA7 phosphorylation at Y106 mediated by the nonreceptor tyrosine kinases c-Abl/Arg. BRCA1 specifically functions as an E3 ubiquitin ligase of PSMA7 ubiquitination. c-Abl/Arg regulates cellular proteasome abundance by controlling the PSMA7 subunit supply. Downregulated PSMA7 level results in decreased proteasome abundance in c-Abl/Arg RNAi-knockdown or c-abl/arg-deficient cells, which demonstrated an increased sensitivity to proteasome inhibition. In response to oxidative stress, the c-Abl-mediated upregulation of proteasome level compensates for the proteasomal activity impairment induced by reactive oxygen species. Abl-kinases-regulated biogenesis and homeostasis of proteasome complexes may be important for understanding related diseases and pathological states.